Article by: Perry Romanowski

With all the fear mongering that goes on about cosmetic preservatives, it is no wonder consumers and some cosmetic manufacturers wonder why they can’t make products without those “nasty” cell-killing chemicals. Well, there is a good reason. Because if preservatives are not included your cosmetics would be too dangerous to use and could spread diseases.

Here is just a sampling of some of the things that preservatives are protecting you from. These microbes have been found growing in cosmetics ranging from lotions, shampoo/conditioners to lipsticks,etc.


Gram Negative Non-Fermentors
Acinetobacter sp. – Can cause life-threatening infections in compromised individuals.
Alcaligenes sp. – Opportunistic infections
Pseudomonas sp.(putida, fluorescens, pausimobilis, aeruginosa, etc) – Second most common infection in hospitals

Gram Negative Fementors
Citrobacter freundii – Can cause life-threatening infections in compromised individuals.

Enterobacter sp. ( agglomerans, aerogenes, gergoviae) –  infections include bacteremia, lower respiratory tract infections, skin infections, soft tissue infections, urinary tract infections, UTI, endocarditis, intraabdominal infections, septic arthritis, osteomyelitis, and ophthalmic infections.

Klebsiella sp. (oxytoca, pneumonia) – Causes pneumonia.

Proteus sp. – Causes mastoiditis
Serratia sp. ( marcescens, odorifera rubidaea) – opportunistic pathogen

Gram Positive
Bacillus sp.
Staphylococcus aureus – Staph infections
Staphylococcus epidermidis – Staph infections
Enterococcus sp. – urinary tract infections
Streptococcus sp. – Strep throat.  Meningitis
Propionibacterium sp. – Acne


Candida sp. – Can cause thrush.  Systemic infection kills 40 – 50% of people infected.
Saccharomyces sp. – Food spoilage
Torula sp.
Zygosaccharomyces sp.


Absidia sp. – Causes Mucormycosis…ewh.
Alternaria sp. – Human allergen
Aspergillus sp. -Produces aflatoxin which is both a toxin and a carcinogen
Citromyces sp.
Cladosporium sp. – reported to cause infections of the skin and toenails
Dematium sp.
Fusarium sp. – Infections may occur in the nails or the cornea
Helminthosporium sp.- Asthma and respiratory infections
Hormodendrum sp. – Allergies
Mucor sp.
Geotrichum sp. – Causative agent of geotrichosis
Paecilomyces sp.
Penicillium sp.
Phoma sp. – Can cause cutaneous or subcutaneous infections.
Aureobasidium sp. – Can damage lungs
Rhizopus sp. – Can cause a fatal fungal infection zygomycosis
Thamnidium sp.
Trichothecium sp.
Verticillium sp.

So the next time you’re thinking about slathering on a personal care product that hasn’t been properly preserved, just think about all the microbes that you could be putting on.  And then imagine those same microbes wrecking havoc on your immune system.

Is that really worth it to you or your customer?

Reference: Brannan, Daniel K. Ed., Cosmetic Microbiology: A Practical Handbook. CRC Press , Boca Raton, FL., 1997. Chapter 2.


  1. Pingback:Hormodendrum allergy | Johnbyk

  2. Avatar

    This frequently amazes me just how Blog owners such as yourself can find the time and also the commitment to carry on Writing terrific blog posts your site is terrific and one of my own must read weblogs, I was more than amazed with the blog post Why are there preservatives in cosmetics I simply needed to thank you and well done Best wishes horny

  3. Avatar

    Talking about fear inducing, Perry, yuck!!! LOL
    One of my microbiology teachers once told me: there is no filthier animal than the human! So while I love my preservatives, I agree with Duncan (the finger image, OMG Duncan, double yuck! LOL): the human using our beloved clean product can turn it very nasty very quickly.

    I guess best stability testing would be: giving away free products to be ‘misused’ by a few filthy human volunteers 😉 for at least 1 year and then take some samples for under the microscope.

  4. Avatar

    The good old Pseudomonas are the ones you need to take a long hard look at in any manufacturing plant as they will breed like wildfire in any stationary water, and they’re tenacious. Good plant hygeine should keep them under control, but sometimes you’ll have to go the for the Ripley Option and “Nuke ’em from orbit” also known as a deep clean.

    For formulators who like loads of natural plant bits in their products, yeasts and moulds can be a problem, as spores will often come in with vegetable matter.

    But the number one contamination source is quite often the end consumer. We’re covered in bugs. Think about it, is your shower gel standing in grubby water in the soap dish? Did you sterilise your finger after having that really satisfying scratch?
    Of course you did, but a lot of people don’t, and then they dip their fingers in your pot of cream. Unless you’re making sterile single use packs, microbial robustness is important, and even then the amount of people who try to eak out 2 or 3 uses out of a single use pack isn’t insignificant

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.